Method of ventilating the productive areas of a coal mine



Nov. 11, 1958 v J. F. JOY E l 2,359,682

METHOD oF VENTILATIANG THE PRoDUcTJ-.VE AREAS oF A com. MINE Filed June 30, 1952 r@ M/NE AIR SUPPLY 7a M//VE EXHAUST DUCT x 50 Li D COA L T 7\ -5 2 kf M 3 & /0 /0 l f7 l .SOLID COAL SOLID COAL Unite States Patent O M METHOD F VENTILATING THE PRODUCTIVE AREAS 0F A COAL MINE Joseph F. Joy, Pittsburgh, Pa., assigner to Joy Manun facturing Company, Pittsburgh, Pa., a corporation or Pennsylvania Application June 30, 1952, Serial No. 296,327

3 Claims. (Cl. 98-50) This invention relates to a mine Ventilating method and more particularly to an improved method of Ventilating the productive areas of a coal mine.

In conventional systems of coal mining the roof area in adjacency to the working face is usually supported by roof props and the mining equipment operates in the space between the face and the prop line, and the face extends from a main entry or cross roadway with the air course extending from the entry along the face so that frsh air may pass over all productive equipment at the face. The space at the face is, however, usually relatively restricted and due to such spacial restriction and the relatively close propping of the roof, the ventilation at the productive area is relatively ineiicient.

In a longwall system and particularly in the highly productive, inverted longwall system such as is disclosed in my copending application Serial No. 296,323, filed June 30, 1952, now abandoned, the working face extends between parallel roadways or panel entries and under conditions where the roof subsides as the productive areas are mined out, the air course at the face is substantially reduced or completely cut off at the gob line, and under such circumstances a dangerous gaseous condition may exist,

The present invention contemplates improvements in the Ventilating method of a mine and particularly improvements in the Ventilating method for an inverted longwall system of mining as above referred to in that adequate air courses are provided at the productive areas of the mine under all conditions thereby greatly reducing the hazards of explosions. In accordance with the improved Ventilating method of the present invention a uniform passageway or bore may be formed in the coal seam in parallelism with and just inside or ahead of the .coal face and this passageway or bore may extend between the parallel roadways or panel entries at the ends of the face so that Ventilating air may flow from one roadway through said passageway or bore inside of the face to the other roadway, and parallel Ventilating bores or breaks-throughs may be formed perpendicular to the face and traversing said passageway or bore so that the productive areas are adequately Ventilated with fresh incoming air flowing over all productive equipment at the face. The improved method also provides for the thorough ventilation of falls and gob lines, thus preventing the accumulation of gas hazards therein.

An object of the present invention is to provide an improved method of Ventilating a mine. Another object is to provide an improved method of Ventilating the productive areas of a coal mine. Other objects and advantages of the invention will, however, hereinafter more fully appear in the course of the ensuing description.

In the accompanying drawing which illustrates the improved ventilating method,

Fig. l is a horizontal schematic sectional View showing the improved Ventilating method applied to the conventional longwall mining system.

Fig. 2 is a cross section taken on line 2--2 of Fig. l,

CII

'2,859,682 Patented Nov. 11, 1958 showing the roof subsidence at the face with the gob line spaced from the face.

Fig. 3 is a schematic horizontal section similar to Fig. 1 showing the improved Ventilating method applied to the so-called bore and sprag system of mining.

Fig. 4 is a cross section taken on line 4-4 of Fig. 3, showing the roof subsidence with the gob line close to or against the face.

The improved Ventilating method of the present invention is, for illustrative purposes, shown associated with the modified or so-called inverted longwall system as disclosed in my copending application, Serial No. 296,323, above referred to, and in such a system the coal is mined out at an extremely rapid rate so that the ventilation at the producing face of the mine must be unusually eective due to the rapid removal of coal from the solid.

In Figs. 1 and 2, the coal face is designated l, the parallel roadways or panel entries at the ends of the face are designated 2 and 3, and the gob or roof fall is designated 4. ln this embodiment the roof subsidence is gradual with the gob line 5 spaced back from the face so that an air space 6' is provided which extends longitudinally of the face between the roadways. Extending horizontally in the coal seam in parallelism with and just inside or ahead of the coal face is a passageway or bore 7 which may desirably be formed by means of a bore miner as disclosed in my copending application, Serial No. 296,324, filed lune 30, 1952, now Patent No. 2,822,- 159, and this passageway or bore extends between the roadways or panel entries 2 and 3, in the manner shown. A series of cross bores or breakthroughs 8 extend at right angles to the face and traverse the passageway or bore 7 and these cross bores communicate with the air space 6 at the face, as shown in Fig. 2. Any number of parallel passageways or bores 7 may be provided as may be necessary for the proper Ventilation of the working area and, in this instance, a parallel bore has been started in the coal seam as indicated at 9 and certain of the cross bores or break-throughs 8 communicate with this partially formed bore. Suitable stoppings l0 may be inserted in certain of the cross bores or break-throughs S so that the greatest amount of fresh air circulates along the portion of the face where coal is being actually mined out, and as disclosed in the above mentioned application, Serial No. 296,323, a mining machine may operate in the passageway or bore 7 to remove the sprag of coal 11 between the bore 7 and the face. As the coal is mined out the roof gradually subsides in back of the face, as shown in Fig. 2. Fresh Ventilating air may be drawn into the roadway or panel entry 2 which provides the intake airway and this air may flow through the passageway or bore 7 and certain of the break-throughs or cross bores 8, so that the air flows along the working face and away from the latter, with the exhaust air flowing out through the other roadway or panel entry 3 `which provides the return airway and which is ventilated by a usual mine exhaust fan located at the surface.

The Ventilating circuit may consist of bringing the fresh air in through the main panel entry and through the roadway 2 and passing it through the required number of bores or passageways 7 to the roadway 3 which forms the back air course which should be sufficient in size rapidly to pass the return air current back to the main return air course. With this arrangement of ventilation the fresh incoming air passes through the space at the coal face and flows over all productive equipment at the face. This arrangement also provides for the thorough ventilation of falls and gob lines thus preventing the accumulation of gas hazards therein.

In Figs. 3 and 4, a horizontal passageway or bore 7' extends in parallelism and just inside or ahead of the coal face 1' and this passageway or bore extends between the shown.

3; roadways or panel entries 2 and 3. Formed in the coal seam in parallelism with the passageway or bore 7' is a second parallel horizontal passageway or bore 7 located morevremote from `the coal face and a third parallel passageway 9' has been started more remote from the face than the second parallel passageway, in the manner Cross bores or break-throughs 8 are formed in the coal seam at right angles to the coal face and traverse the parallel bores 7 and these break-throughs extendgoutthrough the working face and certain of the breakthroughs communicate with the partially formed v.bore-,9' as shown. Operatingin the bore 7 nearest to the face is a coal cutting machine 12 for removing the .sprag of coal11' betweenthe face and the adjacent parallel bore in the manner fully disclosed in my copend- ,ing application, Serial No. 296,323, above referred to.

Extending from this cross cutting machine is a con- V'veyor 13 which extends out through the bore parallel with the face and discharges onto a conveyor 14 in the panel entry 2. As the coal cutting machine 12 removes the sprag of coal, the roof is allowed to subside back of the face and, under the conditions disclosed, as the roof subsides the gob line is brought close against the face so that the ow of Ventilating air along the face is substantially interrupted or completely cut oi by the closely packed gob, as indicated at 15. Stoppings or plugs 10 lmay be inserted in certain of the cross bores of breakthroughs 8 to cut off ow of air therethrough so that the distribution of fresh air may be controlled thereby causing the greatest amount of air to be concentrated at Vthe area of the face where the coal is being actually mined out, and as the roof subsides air circulates through both of the parallel bores 7 as it ows from the roadway v2 to exhaust in the roadway 3.

bores in the coal seam in parallelism and inside of the v coal face and by removing the coal at the face by equipment located in the adjacent bore not only is the ventilation at the face greatly improved but also the safety factor has been greatly enhanced. These and other advantages of the improved method will be clearly apparent to those skilled in the art.

While there are in this application specifically disclosed two Variations of the improved method by which the invention may be practiced, it will be understood that these are shown for purposes of illustration and that the invention may be practiced in other manners without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

l. A method of Ventilating a productive area of a coal mine comprising the formation of parallel horizontal passageways in a coal seam in parallelism with an advance face of a productive area with one passageway in adjacency to and just inside of said face and another passageway more remote from said face, said passageways extending between intake and return airway passages extending at right angles to said face at the opposite ends of the latter, and parallel horizontal cross breakthrough bores extending at right angles to said face and traversing said parallel horizontal passageways, and effecting a flow of Ventilating air inwardly from the intake passage through said parallel passageways and said cross bores to said return passage and outwardly through the latter.

2. A method of Ventilating mines as set forth in claim l wherein certain of said cross break-through bores may be blocked 01T from communication with said face of said productive area and with certain of said parallel passageways to obtain controlled distribution of air through said parallel passageways and certain of said cross bores whereby the largest volume of flow of fresh air is concentrated at said face of said productive area.

3. A method of Ventilating a productive area of a coal mine comprising the steps of forming parallel horizontal bores just inside of and parallel with an advance face of a productive area with said bores communicating with parallel intake and return airway passages extending at right angles to said face at the opposite ends of the latter', there being an upright sprag of coal left between said face and the nearest bore and a parallel sprag between said bores, a series of openings extending through said sprag of coal between said face and the nearest bore and also through said sprag of coal between said bores, and eiecting a flow of Ventilating air inwardly through the intake passage, along said bores in parallelism with the face and through certain of said openings to said return passage and outwardly through the latter.

References Cited in the tile of this patent UNITED STATES PATENTS 922,603 Laws May 25, 1909 942,950 Ward Dec. 14, 1909 1,586,660 Dodds June l, 1926 2,651,513 Ramsey Sept. 8, 1953 FOREIGN PATENTS 884,201 France Apr. 12, 1943 

